Phase-shift engineered triboelectric nanogenerators for constant-voltage output and efficient energy harvesting

Triboelectric nanogenerators (TENGs) have emerged as a promising technology for harvesting ambient mechanical energy, their practical deployment has been strongly underpinned by their excellent inherent capabilities for ambient mechanical energy harvesting. Phase-shift engineering, which modulates the phase shifts of electrical outputs from multiple TENG units to achieve continuous constant voltage/current output, further unlocking their full potential and boosting energy utilization efficiency and practicality. This review comprehensively summarizes the fundamental principles of phase-shift engineered TENGs, core design strategies (including inter-unit and intra-unit phase-shift designs, as well as charge excitation-coupled phase-shift approaches), and the efficient energy transport characteristics of CV-TENGs derived from phase-shift engineering. Furthermore, it highlights key challenges like precision manufacturing and environmental robustness, along with future directions of multi-energy coupling and high-end application expansion, providing systematic guidance for high-performance, practical CV-TENG development. Phase-shift engineering of triboelectric nanogenerators (TENGs) is a strategy for modulating the phase shifts of electrical output from multiple TENG units to achieve continuous constant voltage/current output. This Review summarizes the principles of phase shift engineered TENGs, and how it might further boost energy utilization efficiency and practicality.